1. Technical Field
The present invention relates to a semiconductor device and a method for manufacturing the same.
2. Description of the Related Art
A semiconductor wafer having a plurality of integrated circuits formed by a series of manufacturing processes is cut into individual semiconductor chips. In general, a wafer sawing equipment is used in cutting a semiconductor wafer.
A sawing blade is generally used as a wafer sawing equipment. A laser beam can be also used. A semiconductor wafer is divided into unit chips using the sawing blade.
Sawing process using a blade can be also applied in division of a substrate strip, on which a semiconductor chip is mounted, into unit semiconductor chip packages. Hereinafter, a conventional method for manufacturing a semiconductor device will be described referring to the following drawings.
FIGS. 1A to 1E are cross-sectional views illustrating a conventional method for manufacturing a semiconductor device.
As shown in FIG. 1A, a first insulating layer 11 is formed on a semiconductor substrate (not shown) having a semiconductor chip region and a scribe region.
Then, portions of the first insulating layer 11 is selectively removed to expose a surface of the semiconductor substrate, using photolithography and etching processes, thus forming a contact hole 12.
Referring to FIG. 1B, a metal layer for a contact plug is deposited over an entire surface of the semiconductor substrate, filling the contact hole 12. The substrate then undergoes a chemical mechanical polishing (CMP) process, thus forming a metal contact plug 13 within the contact hole 12.
Next, as shown in FIG. 1C, another metal layer for a metallization wiring is deposited over the entire surface of the substrate, and is selectively removed by photolithography and etching processes, thus forming the metallization wiring 14 electrically connected with a predetermined circuit element on the substrate via the metal contact plug 13.
As shown in FIG. 1D, a second insulating layer 15 is formed over the entire surface of the substrate including the metallization wiring 14, and then a protective layer 16 is formed on the second insulating layer 15.
After forming the protective layer 16, the substrate is divided into unit chips by a sawing process at the scribe region. FIG. 1E shows the side surface “A,” which is exposed to the atmosphere by the sawing process.
The above-described conventional method for manufacturing a semiconductor device has a number of problems. Particularly, even though the top surface of the divided unit chip is protected by the protective layer 16, the side surfaces of the second insulating layer 15 and the first insulating layer 11 are exposed to the atmosphere by the sawing process. Accordingly, oxygen or nitrogen in the atmosphere may penetrate into the semiconductor chip through the exposed surfaces of the second insulating layer 15 and the first insulating layer 11, thus resulting in deterioration of the semiconductor chip.